Luminous energy control



adv'dvd v a Jan. 17, 1933. c. L. DAVIS LUMINOUS ENERGY CONTROL Filed April 25, 1929 M6 CIR "ro MOOULRT/ON cu: aun- CIR Patented Jan. 17, 1933 UNITED STATES PATENT OFFICE CHESTER L. DAVIS, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR '10 WIRED RADIO, INC., OF NEW YORK, N. Y.,

A CORPORATION OF DELAWARE LUMINOUS ENERGY CONTROL Application filed April 25, 1929. Serial No. 358,107.

My invention relates to luminous energy control and more particularly to a method and means for modulating a source of luminous energy of constant intensity.

An object of my invention is to provide a method of modulating a constant source of luminous energy.

Another object of my invention is to provide a method for accurately controlling a source of luminous energy of constant intensity in accordance with variations of electrical energy.

A further object of my invention is to pro vide a light energy modulating system wherein a source of low intensity variable light energy controls a source of high intensity constant light energy.

A better understanding of my invention can be had from the specification following and from the accompanying drawing wherein:

Figure 1 shows one form of my invention; Fig. 2 shows a second form of my invention which I shall call direct control; Fig. 3 shows a plane surface reflector embodying my invention; Fig. 4 shows a parabolic reflector embodying my invention and Fig. 5 shows a schematic circuit diagram illustrating one application of my invention.

In the control of luminous energy many methods have heretofore been employed, among them electromagnetically operated shutters, electromagnetically operated mirrors and other methods too numerous to mention. In the use of a glow-discharge tube the intensity of the generated luminous energy is somewhat limited due to several reasons. Other types of tubes employing a filamentary member are not suflieiently responsive for use in the transmission and reception of pictures, the recording of sound by photographic methods and the like. By my method and means for controlling the intensity of luminous energy it is possible to control an unlimited amount of luminous energy accurately and in accordance with a source of electrical energy modulated by a given frequency.

The essential principle involved in the present invention, is that certain gases when excited by a certain value of potential, de-

pending upon the gas employed, will ionize and give ofi luminous energy. This is familiar in the use of glow discharge tubes generally where a difference of potential exists in an evacuated vessel where a quantity of an inert gas exists. It is common to employ such gases as neon, argon, krypton, helium and the like where different colors are emitted, depending upon the gas employed. I have found that a medium of ionized gas when giving off luminous energy of suflicient intensity will obstruct the rays of luminous energy directed through this medium.

The rays of luminous energy may be from a source A and caused to reflect from an electrode C which is highly polished, as shown in Fig. 1. Electrodes C and D are enclosed in bulb B which has been evacuated and in which a small quantity of an inert gas has been introduced. By connecting a source of variable or modulated electrical energy to the terminals leading to electrodes C and D a glow will be developed on the polished surface of C. This glow in the case of neon, is of a pink color. The '10 the io ization of the gas. ray of light lIlCldent upon led surface of electrode C will be reflected along the line in the direction E. The intensity of the reflected luminous energy from electrode C to point IE will depend upon the reflecting ability of electrode C, which'as heretofore mentioned is very high. The ionization and luminous energy control the intensity of the reflected energy in proportion to the electrical energy exciting the electrodes C and D.

Fig. 2 shows a modification of my invention wherein the energy from constant source A is directed through the ionized medium and not reflected as in the arrangement shown in Fig. 1. By employing the proper inert gases in bulb B for the source of luminous energy A it is possible to accurately control a large quantity of energy. This will be. governed by source A determining the ionization necessary to effect a complete control. Bulb B may take the form of an elongated tube where the energy from source A is directed through the entire length of the tube and consequently through a greater quantity of ionized gas. Any number of tubes may be connected in series to effect the proper control.

Fig. 3 shows electrodes C and D comprising flat plates rather than the semi-cylindrical plates shown in Fig. 1. The plates correspond to the electrodes C and D shown in Fig. 1. The reflection surface method is very satisfactory for many purposes. Fig. it shows the electrodes C and D" shaped as parabolic reflectors and wherein luminous energy from source A is directed to the polished reflecting surface of electrode C by means of reflector A. Greater concentration by such an arrangement is possible.

Fig. 5 is a schematic diagram and arrangement showing one application of my invention. Luminous energy from source A is directed upon elect-rode C from which itis reflected in the direction E. The energy may be suitably restricted by shutters, slits, lens or other means to a given portion of lightsensitive film F. The terminals leading from an amplifier G are connected to the electrodes C and D. The variable electrical energy from amplifier G controls the intensity of the luminous energy reflected by electrode G by controlling the luminous glow of the ionized gas in bulb B and particularly the glow immediately adjacent to electrode C.

When direct current is employed to effect ionization the glow is principally concentrated near the cathode. Therefore the cathode is usually employed as the reflecting electrode. \Vhen alternating current. is employed the electrodes are alternately the cathode and anode therefore the glow will be distributed rather than concentrated on the surface of either electrode alone.

Many different combinations are possible in the choice of the gas employed, or combination of gases. Thus for different colors certain combinations are best while other colods require different combinations. The electrodes may be of any suitable shape or size and of any suitable material. Thus, the inminous energy may be controlled by a sil- .vered glass where the electrodes are not common with the reflector but adjacent thereto sufficiently to provide the ionized luminous glow discharge. The electrodes may be po sitioned in any suitable manner desired.

I realizethat many modifications of my invention are possible without departing from the spirit of my invention. In Fig. 5 the input of amplifier G may be a microphone, or the energy may be delivered from a television receiver or any other suitable source of electrical energy maybe employed. I realize that many modifications and applications of my method and means for controlling the intensity of a source of luminous energy are possible other than those shown in the accompanying drawing and referred to in the foregoing specification and it is to be strictly understood that my invention shall not be restricted by the foregoing specification or by the accompanying drawing but only by the scope of the appended claims.

lVhat I claim as new aiid desire to secure by Letters Patent of the United States is as follows:

1. A modulating reflector for luminous energy comprising a pair of glow discharge electrodes disposed in an ionizing atmosphere, a modulation circuit for controlling the luminosity of the glow discharge from said electrodes, means for directing light rays upon said glow discharge electrodes and shaped surfaces on said electrodes for deflecting the rays therefrom to .a predetermined focal point, the reflected energy being proportional in intensity to the ionization of gi igiphcneadjacent said ele tc r'odest r modulatlng reflector for luminous en- 8 ergy comprising a light transparent vessel enclosing an ionizable atmosphere, a pair of parabolic shaped glow discharge electrodes within said vessel, a modulation circuit connected with said electrodes for establishinga variably ionized condition of the atmosphere adjacent said electrodes, a source of light directed upon said parabolic shaped electrodes, said electrodes operating to reflect a beam of light from said source and concentrate said beam of light at the focal point of said parabolic electrodes, said beam of light having the intensity thereof controlled by the variable ionization of the atmosphere adjacent said electrodes in accordance with the operation of said modulation circuit.

3. A device for reflecting modulated luminous energy comprising an enclosing vessel containing an inert gas, a pair of curvilinear glow discharge electrodes each having the same radius of curvature and spaced one from the other to provide a glow discharge gap, means for directing light rays upon the concave surface of one of said electrodes, the curvature of said lastmentioned electrode de-' termining the reflection of said light rays and means for subjecting said electrodes to varying degrees of luminosity for proportionally varying the intensity of the reflected light.

In testimony whereof I aflix my signature.

CHESTER L. DAVIS. 

